This article presents the various collections of Judaica and Hebraica and their areas of special focus in chronological order of their acquisition at the Potsdam University Library. Aside from those collections which include works in all areas of Jewish Studies, such as the Israel Mehlmann Library or the Israil Bercovici Library,the Aschkenasy Library has the most valuable holdings. It includes the earlier library of Bet ha-Midrasch, which was founded by Veitel Heine Ephraim, a banker and the royal jeweler of Prussia's King Friedrich the Great. The Aschkenasy Collection consists notonly of numerous titles of traditional Judaic literature published since 1550, but also research literature and 58 Yemenite manuscripts dating from the 17th and 18th century.